Continuation methods for adapting simulated skills

ABSTRACT

Modeling the large space of possible human motions requires scalable techniques. Generalizing from example motions or example controllers is one way to provide the required scalability. We present techniques for generalizing a controller for physics-based walking to significantly different tasks, such as climbing a large step up, or pushing a heavy object. Continuation methods solve such problems using a progressive sequence of problems that trace a path from an existing solved problem to the final desired-but-unsolved problem. Each step in the continuation sequence makes progress towards the target problem while further adapting the solution. We describe and evaluate a number of choices in applying continuation methods to adapting walking gaits for tasks involving interaction with the environment. The methods have been successfully applied to automatically adapt a regular cyclic walk to climbing a 65cm step, stepping over a 55cm sill, pushing heavy furniture, walking up steep inclines, and walking on ice. The continuation path further provides parameterized solutions to these problems.

REFERENCES

• 1: Yeuhi Abe , C. Karen Liu , Zoran Popović, Momentum-based parameterization of dynamic character motion, Proceedings of the 2004 ACM SIGGRAPH/Eurographics symposium on Computer animation, August 27-29, 2004, Grenoble, France [doi>10.1145/1028523.1028546]
• 2: Joel Auslander , Alex Fukunaga , Hadi Partovi , Jon Christensen , Lloyd Hsu , Peter Reiss , Andrew Shuman , Joe Marks , J. Thomas Ngo, Further experience with controller-based automatic motion synthesis for articulated figures, ACM Transactions on Graphics (TOG), v.14 n.4, p.311-336, Oct. 1995 [doi>10.1145/225294.225295]
• 3: da Silva, M., Abe, Y., and Popović, J. 2008. Simulation of human motion data using short-horizon model-predictive control. Computer Graphics Forum (Proc. Eurographics) 27, 2.
• 4: Petros Faloutsos , Michiel van de Panne , Demetri Terzopoulos, Composable controllers for physics-based character animation, Proceedings of the 28th annual conference on Computer graphics and interactive techniques, p.251-260, August 2001 [doi>10.1145/383259.383287]
• 5: Radek Grzeszczuk , Demetri Terzopoulos, Automated learning of muscle-actuated locomotion through control abstraction, Proceedings of the 22nd annual conference on Computer graphics and interactive techniques, p.63-70, September 1995 [doi>10.1145/218380.218411]
• 6: Jessica K. Hodgins , Nancy S. Pollard, Adapting simulated behaviors for new characters, Proceedings of the 24th annual conference on Computer graphics and interactive techniques, p.153-162, August 1997 [doi>10.1145/258734.258822]
• 7: Jessica K. Hodgins , Wayne L. Wooten , David C. Brogan , James F. O'Brien, Animating human athletics, Proceedings of the 22nd annual conference on Computer graphics and interactive techniques, p.71-78, September 1995 [doi>10.1145/218380.218414]
• 8: Joseph Laszlo , Michiel van de Panne , Eugene Fiume, Limit cycle control and its application to the animation of balancing and walking, Proceedings of the 23rd annual conference on Computer graphics and interactive techniques, p.155-162, August 1996 [doi>10.1145/237170.237231]
• 9: C. Karen Liu , Aaron Hertzmann , Zoran Popović, Composition of complex optimal multi-character motions, Proceedings of the 2006 ACM SIGGRAPH/Eurographics symposium on Computer animation, September 02-04, 2006, Vienna, Austria
• 10: Nocedal, J., and Wright, S. J. 1999. Numerical Optimization. Springer.
• 11: Zoran Popović , Andrew Witkin, Physically based motion transformation, Proceedings of the 26th annual conference on Computer graphics and interactive techniques, p.11-20, July 1999 [doi>10.1145/311535.311536]
• 12: Marc H. Raibert , Jessica K. Hodgins, Animation of dynamic legged locomotion, Proceedings of the 18th annual conference on Computer graphics and interactive techniques, p.349-358, July 1991
• 13: Alla Safonova , Jessica K. Hodgins , Nancy S. Pollard, Synthesizing physically realistic human motion in low-dimensional, behavior-specific spaces, ACM Transactions on Graphics (TOG), v.23 n.3, August 2004
• 14: Seeger, A. 2006. Recent Advances in Optimization. Springer.
• 15: Sharon, D., and van de Panne, M. 2005. Synthesis of controllers for stylized planar bipedal walking. In International Conference on Robotics and Automation.
• 16: Kwang Won Sok , Manmyung Kim , Jehee Lee, Simulating biped behaviors from human motion data, ACM Transactions on Graphics (TOG), v.26 n.3, July 2007
• 17: James C. Spall, Introduction to Stochastic Search and Optimization, John Wiley & Sons, Inc., New York, NY, 2003
• 18: A. James Stewart , James F. Cremer, Beyond keyframing: an algorithmic approach to animation, Proceedings of the conference on Graphics interface '92, p.273-281, September 1992, Vancouver, British Columbia, Canada
• 19: Adnan Sulejmanpašić , Jovan Popović, Adaptation of performed ballistic motion, ACM Transactions on Graphics (TOG), v.24 n.1, p.165-179, January 2005 [doi>10.1145/1037957.1037966]
• 20: Adrien Treuille , Antoine McNamara , Zoran Popović , Jos Stam, Keyframe control of smoke simulations, ACM Transactions on Graphics (TOG), v.22 n.3, July 2003
• 21: Michiel van de Panne , Eugene Fiume, Sensor-actuator networks, Proceedings of the 20th annual conference on Computer graphics and interactive techniques, p.335-342, August 02-06, 0093, Anaheim, CA [doi>10.1145/166117.166159]
• 22: van de Panne, M., and Lamouret, A. 1995. Guided optimization for balanced locomotion. In Proc. EG Workshop on Computer Animation and Simulation, 165--177.
• 23: Michiel van de Panne, Parameterized Gait Synthesis, IEEE Computer Graphics and Applications, v.16 n.2, p.40-49, March 1996 [doi>10.1109/38.486679]
• 24: Andrew Witkin , Michael Kass, Spacetime constraints, Proceedings of the 15th annual conference on Computer graphics and interactive techniques, p.159-168, June 1988
• 25: Wayne Lewis Wooten , Jessica K. Hodgins, Simulation of leaping, tumbling, landing, and balancing humans, Georgia Institute of Technology, Atlanta, GA, 1998
• 26: KangKang Yin , Kevin Loken , Michiel van de Panne, SIMBICON: simple biped locomotion control, ACM Transactions on Graphics (TOG), v.26 n.3, July 2007

INDEX TERMS

Primary Classification:
  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.7 Three-Dimensional Graphics and Realism

Additional Classification:
  I. Computing Methodologies
  I.2 ARTIFICIAL INTELLIGENCE
      I.2.8 Problem Solving, Control Methods, and Search
          Subjects: Control theory
  I.3 COMPUTER GRAPHICS
      I.3.5 Computational Geometry and Object Modeling
          Subjects: Physically based modeling
  I.6 SIMULATION AND MODELING
      I.6.5 Model Development
          Subjects: Modeling methodologies

General Terms:
Algorithms, Design, Theory